百度座標轉換，以及國測局、WGS84（GPS）座標系之間的轉換札記

背景介紹

    座標系轉換，網上內容也比較多、也比較雜，有的可以運行，有的則各種問題，這裏記錄並加以補充，最後封裝了常用座標系轉換工具。親測可運行！

• WGS84：即地球座標系，國際上通用的座標系。谷歌地圖採用的是WGS84地理座標系（中國範圍除外）
• GCJ02：即火星座標系，中國國家測繪局制訂。由WGS84座標系經加密而成，谷歌中國地圖和搜搜中國均採用的是GCJ02
• BD09ll：即百度座標系，經GCJ02加密後的座標系，百度座標系除了baidu09ll之外還有baidu09mc（墨卡託座標）座標
• 搜狗座標系、圖吧座標系等也是在GCJ02基礎上加密而成

座標轉換接口

先定義一個表示座標的JavaBean:

/**
 * @author [email protected]
 * @since 0.1.0
 **/
public class CoordinateBean {
    /**
     * 定位的幾個基本信息
     */
    private double longitude;

    private double latitude;

    private boolean isChina;

    public CoordinateBean() {

    }

    public CoordinateBean(double longitude, double latitude) {
        this.longitude = longitude;
        this.latitude = latitude;
    }

    public double getLongitude() {
        return longitude;
    }

    public void setLongitude(double longitude) {
        this.longitude = longitude;
    }

    public double getLatitude() {
        return latitude;
    }

    public void setLatitude(double latitude) {
        this.latitude = latitude;
    }

    public boolean isChina() {
        return isChina;
    }

    public void setChina(boolean china) {
        this.isChina = china;
    }

    @Override
    public String toString(){
        return this.latitude + "_" + this.longitude;
    }

}

座標轉換工具類：

/**
 *
 * @author [email protected]
 * @since 0.1.0
 *
 */

public class PositionConvertUtil {

    private static final double A = 6378245.0;
    private static final double PI = 3.1415926535897932384626;
    private static final double EE = 0.00669342162296594323;
    private static final double LON_BOUNDARY_MIN = 72.004;
    private static final double LAT_BOUNDARY_MIN = 0.8293;
    private static final double LON_BOUNDARY_MAX = 137.8347;
    private static final double LAT_BOUNDARY_MAX = 55.8271;
    private static final double X_PI = 3.14159265358979324 * 3000.0 / 180.0;

    /**
     * wgs84  to   gcj02
     * @param lat lat
     * @param lon lon
     * @return coordinate
     */
    public CoordinateBean wgs84ToGcj02(double lat, double lon) {
        CoordinateBean info = new CoordinateBean();
        if (outOfChina(lat, lon)) {
            info.setChina(false);
            info.setLatitude(lat);
            info.setLongitude(lon);
        }else {
            double dLat = transformLat(lon - 105.0, lat - 35.0);
            double dLon = transformLon(lon - 105.0, lat - 35.0);
            double radLat = lat / 180.0 * PI;
            double magic = Math.sin(radLat);
            magic = 1 - EE * magic * magic;
            double sqrtMagic = Math.sqrt(magic);
            dLat = (dLat * 180.0) / ((A * (1 - EE)) / (magic * sqrtMagic) * PI);
            dLon = (dLon * 180.0) / (A / sqrtMagic * Math.cos(radLat) * PI);
            double mgLat = lat + dLat;
            double mgLon = lon + dLon;
            info.setChina(true);
            info.setLatitude(mgLat);
            info.setLongitude(mgLon);
        }
        return info;
    }

    /**
     * gcj02  to  wgs84
     * @param lat lat
     * @param lon lat
     * @return coordinate
     */
    public CoordinateBean gcj02ToWgs84(double lat, double lon) {
        CoordinateBean info = new CoordinateBean();
        CoordinateBean gps = transform(lat, lon);
        double lontitude = lon * 2 - gps.getLongitude();
        double latitude = lat * 2 - gps.getLatitude();
        info.setChina(gps.isChina());
        info.setLatitude(latitude);
        info.setLongitude(lontitude);
        return info;
    }

    /**
     * 百度座標系 (BD-09ll) 與 火星座標系 (GCJ-02)的轉換
     * 即 百度 轉 谷歌中國、高德
     * @param bdLat bdLat
     * @param bdLon bdLon
     * @return coordinate
     */
    public CoordinateBean bd09tToGcj02(double bdLat,double bdLon){
        double x = bdLon - 0.0065;
        double y = bdLat - 0.006;
        double z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * X_PI);
        double theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * X_PI);
        double ggLng = z * Math.cos(theta);
        double ggLat = z * Math.sin(theta);
        return new CoordinateBean(ggLng,ggLat);
    }



    /**
     * 火星座標系 (GCJ-02) 與百度座標系 (BD-09ll) 的轉換
     * 即谷歌中國、高德 轉 百度
     * @param lon lng
     * @param lat lat
     * @return coordinate
     */
    public CoordinateBean gcj02ToBd09(double lat, double lon){
        double z = Math.sqrt(lon * lon + lat * lat) + 0.00002 * Math.sin(lat * X_PI);
        double theta = Math.atan2(lat, lon) + 0.000003 * Math.cos(lon * X_PI);
        double bdLng = z * Math.cos(theta) + 0.0065;
        double bdLat = z * Math.sin(theta) + 0.006;
        return new CoordinateBean(bdLng,bdLat);
    }

    /**
     * baidu09ll to wgs84
     * 即谷歌中國、高德 轉 百度
     * @param lat lat
     * @param lon lng
     * @return coordinate
     */
    public CoordinateBean baidu09ToWgs84(double lat, double lon){
        CoordinateBean info = bd09tToGcj02(lat,lon);
        info = gcj02ToWgs84(info.getLatitude(),info.getLongitude());
        return info;
    }

    /**
     * 這裏的傳參是WGS84 即gps座標
     * @param lat lat
     * @param lon lon
     * @return boolean
     */
    private boolean outOfChina(double lat, double lon) {
        if (lon < LON_BOUNDARY_MIN || lon > LON_BOUNDARY_MAX){
            return true;
        }
        return lat < LAT_BOUNDARY_MIN || lat > LAT_BOUNDARY_MAX;
    }

    private double transformLon(double x, double y) {
        double ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1
                * Math.sqrt(Math.abs(x));
        ret += (20.0 * Math.sin(6.0 * x * PI) + 20.0 * Math.sin(2.0 * x * PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(x * PI) + 40.0 * Math.sin(x / 3.0 * PI)) * 2.0 / 3.0;
        ret += (150.0 * Math.sin(x / 12.0 * PI) + 300.0 * Math.sin(x / 30.0 * PI)) * 2.0 / 3.0;
        return ret;
    }

    private double transformLat(double lng,double lat) {
        double ret = -100.0 + 2.0 * lng + 3.0 * lat + 0.2 * lat * lat + 0.1 * lng * lat + 0.2 * Math.sqrt(Math.abs(lng));
        ret += (20.0 * Math.sin(6.0 * lng * PI) + 20.0 * Math.sin(2.0 * lng * PI)) * 2.0 / 3.0;
        ret += (20.0 * Math.sin(lat * PI) + 40.0 * Math.sin(lat / 3.0 * PI)) * 2.0 / 3.0;
        ret += (160.0 * Math.sin(lat / 12.0 * PI) + 320 * Math.sin(lat * PI / 30.0)) * 2.0 / 3.0;
        return ret;
    }

    private CoordinateBean transform(double lat, double lon) {
        CoordinateBean info = new CoordinateBean();
        if (outOfChina(lat, lon)) {
            info.setChina(false);
            info.setLatitude(lat);
            info.setLongitude(lon);
            return info;
        }
        double dLat = transformLat(lon - 105.0, lat - 35.0);
        double dLon = transformLon(lon - 105.0, lat - 35.0);
        double radLat = lat / 180.0 * PI;
        double magic = Math.sin(radLat);
        magic = 1 - EE * magic * magic;
        double sqrtMagic = Math.sqrt(magic);
        dLat = (dLat * 180.0) / ((A * (1 - EE)) / (magic * sqrtMagic) * PI);
        dLon = (dLon * 180.0) / (A / sqrtMagic * Math.cos(radLat) * PI);
        double mgLat = lat + dLat;
        double mgLon = lon + dLon;
        info.setChina(true);
        info.setLatitude(mgLat);
        info.setLongitude(mgLon);
        return info;
    }
}

百度座標系之間的轉換（即baidu09ll轉baidu09mc）

/**
 * @author [email protected]
 * @since 0.1.0
 **/
public class CoordinatesConvert {
    private static double[] MCBAND = {12890594.86, 8362377.87, 5591021d, 3481989.83, 1678043.12, 0d};
    private static double[] LLBAND = {75d, 60d, 45d, 30d, 15d, 0d};
    private static double[][] MC2LL = {{1.410526172116255e-8, 0.00000898305509648872, -1.9939833816331, 200.9824383106796, -187.2403703815547, 91.6087516669843, -23.38765649603339, 2.57121317296198, -0.03801003308653, 17337981.2}, {-7.435856389565537e-9, 0.000008983055097726239, -0.78625201886289, 96.32687599759846, -1.85204757529826, -59.36935905485877, 47.40033549296737, -16.50741931063887, 2.28786674699375, 10260144.86}, {-3.030883460898826e-8, 0.00000898305509983578, 0.30071316287616, 59.74293618442277, 7.357984074871, -25.38371002664745, 13.45380521110908, -3.29883767235584, 0.32710905363475, 6856817.37}, {-1.981981304930552e-8, 0.000008983055099779535, 0.03278182852591, 40.31678527705744, 0.65659298677277, -4.44255534477492, 0.85341911805263, 0.12923347998204, -0.04625736007561, 4482777.06}, {3.09191371068437e-9, 0.000008983055096812155, 0.00006995724062, 23.10934304144901, -0.00023663490511, -0.6321817810242, -0.00663494467273, 0.03430082397953, -0.00466043876332, 2555164.4}, {2.890871144776878e-9, 0.000008983055095805407, -3.068298e-8, 7.47137025468032, -0.00000353937994, -0.02145144861037, -0.00001234426596, 0.00010322952773, -0.00000323890364, 826088.5}};
    private static double[][] LL2MC = {{-0.0015702102444, 111320.7020616939, 1704480524535203d, -10338987376042340d, 26112667856603880d, -35149669176653700d, 26595700718403920d, -10725012454188240d, 1800819912950474d, 82.5}, {0.0008277824516172526, 111320.7020463578, 647795574.6671607, -4082003173.641316, 10774905663.51142, -15171875531.51559, 12053065338.62167, -5124939663.577472, 913311935.9512032, 67.5}, {0.00337398766765, 111320.7020202162, 4481351.045890365, -23393751.19931662, 79682215.47186455, -115964993.2797253, 97236711.15602145, -43661946.33752821, 8477230.501135234, 52.5}, {0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5}, {-0.0003441963504368392, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5}, {-0.0003218135878613132, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45}};

    /**
     * 墨卡託座標轉經緯度座標
     * @param x x
     * @param y y
     * @return map
     */
    public Map<String, Double> convertMC2LL(double x, double y) {
        double[] cF = null;
        x = Math.abs(x);
        y = Math.abs(y);
        for (int cE = 0; cE < MCBAND.length; cE++) {
            if (y >= MCBAND[cE]) {
                cF = MC2LL[cE];
                break;
            }
        }
        Map<String,Double> location = converter(x, y, cF);
        location.put("lng",location.get("x"));
        location.remove("x");
        location.put("lat",location.get("y"));
        location.remove("y");
        return location;
    }

    /**
     * 經緯度座標轉墨卡託座標, 已做小數位保留（8位、10位）
     * @param lng lonti
     * @param lat lati
     * @return map
     */
    public String convertLL2MC(Double lng, Double lat) {
        double[] cE = null;
        lng = getLoop(lng, -180, 180);
        lat = getRange(lat, -74, 74);
        for (int i = 0; i < LLBAND.length; i++) {
            if (lat >= LLBAND[i]) {
                cE = LL2MC[i];
                break;
            }
        }
        if (cE!=null) {
            for (int i = LLBAND.length - 1; i >= 0; i--) {
                if (lat <= -LLBAND[i]) {
                    cE = LL2MC[i];
                    break;
                }
            }
        }
        Map<String, Double> map =  converter(lng,lat, cE);
        double x = map.get("x");
        double y = map.get("y");
        BigDecimal xTemp = new BigDecimal(x);
        BigDecimal yTemp = new BigDecimal(y);
        String tempX = xTemp.setScale(8,BigDecimal .ROUND_HALF_UP).toPlainString();
        String tempY = yTemp.setScale(10,BigDecimal .ROUND_HALF_UP).toPlainString();
        return "x="+tempX+"&y="+tempY;
    }

    private Map<String, Double> converter(double x, double y, double[] cE) {
        double xTemp = cE[0] + cE[1] * Math.abs(x);
        double cC = Math.abs(y) / cE[9];
        double yTemp = cE[2] + cE[3] * cC + cE[4] * cC * cC + cE[5] * cC * cC * cC + cE[6] * cC * cC * cC * cC + cE[7] * cC * cC * cC * cC * cC + cE[8] * cC * cC * cC * cC * cC * cC;
        xTemp *= (x < 0 ? -1 : 1);
        yTemp *= (y < 0 ? -1 : 1);
        Map<String, Double> location = new HashMap<>(4);
        BigDecimal tempX = new BigDecimal(xTemp);
        BigDecimal tempY = new BigDecimal(yTemp);
        xTemp = tempX.setScale(8, BigDecimal.ROUND_HALF_UP).doubleValue();
        yTemp = tempY.setScale(8, BigDecimal.ROUND_HALF_UP).doubleValue();
        location.put("x", xTemp);
        location.put("y", yTemp);
        return location;
    }

    private Double getLoop(Double lng, Integer min, Integer max) {
        while (lng > max) {
            lng -= max - min;
        }
        while (lng < min) {
            lng += max - min;
        }
        return lng;
    }

    private Double getRange(Double lat, Integer min, Integer max) {
        if (min != null) {
            lat = Math.max(lat, min);
        }
        if (max != null) {
            lat = Math.min(lat, max);
        }
        return lat;
    }
}

注意

• 座標轉換後存在精度損失，所以多次轉換並反轉後會有些許偏差，但偏差不是很大。
• 這裏給出一個座標轉換的測試鏈接：http://www.gpsspg.com/maps.htm，百度座標可通過百度座標提取器獲取。